I dont know why

Ok so I am almost 30 weeks and last night I was sleeping and my s.o and I live in am apartment without air conditioning so it gets hot and I am from a state where it's hot all year long so my body knows what to do with heat but I woke up last night because my son had fallen asleep I thought something happened because I was feeling kick kick then he got comfortable and fell asleep I kid you not I woke up grabbed my stethoscope and found his heart beat 100% normal I hate this anxiety I cant wait to be holding him in my arms